1. Field
The present invention relates to a semiconductor memory device and a method of manufacturing the same, and more particularly, to a semiconductor memory device including an air gap and a method of manufacturing the semiconductor memory device.
2. Discussion of Related Art
A semiconductor memory device includes a plurality of memory cells for storing data and devices for various operations. High-density integration of the semiconductor memory device has been demanded for large capacity and light weight. Especially, areas of the memory cells occupied in a semiconductor chip is very wide, so that a decrease in sizes of and intervals between the memory cells has continuously become an issue.
In a NAND flash memory device, the memory cells are arranged in the unit of a string, a space between the strings, i.e. an isolation region, is filled with a device separation film formed of an insulating material. The device separation film serves to block an electrical influence i.e. interference, between adjacent strings.
However, as the integration of the semiconductor memory devices is increased, there is a limit in blocking the interference between the strings by the device separation film formed of the insulating material, so that reliability of the semiconductor memory device may deteriorate.